In the liturgy, water is used, especially in the baptism ceremony, to symbolise the "washing away" of original sin. The Virgin Mary - who was herself conceived without sin - used Massabielle Spring, above all, as a symbol to recall the real meaning and the full grace of the first sacrement - baptism - which makes the one baptised "a child of the Church". In a simple act of faith, imitating Bernadette's actions of drinking and washing, pilgrims to Lourdes find purification of body and soul.

But among the sick that flock here, many come to be immersed in its waters, and some are healed. Since the first healing, of Catherine Latapie, on March 1st, 1858, as many as 2,500 unexplained healings have been recorded. But many feel that the true miracle of Lourdes is, above all, the presence and goodness of God, expressed in this "limited bodily Proof of the unlimited grace offered to all" (R. Laurentin).